Effect of interaction and mobility on fixed-bed reactor performance

The roles of interaction and mobility in determining surface rates and hence reactor performance, as reflected in the space time values required for achieving a desired conversion or selectivity, are demonstrated. It is shown that localized adsorption models predict larger space times in comparison to the mobile models. Further, repulsive forces lead to higher space times in comparison to attractive forces, and the divergence between models is most marked for localized adsorption

Impact of Seed-born Colletotrichum lindemuthianum on French Bean Seed Quality

French bean seed samples were collected from different parts of Tamil Nadu including both tropical and temperate region including four cultivars viz.,Arkakomal,Premier,Rajmash DPU 88-4 and Watex.The variety Watex was found to maximum per cent seed infection of C.lindemuthianum with more discolorations.Among the various techniques adopted for detection,agar plate method was found to be best and yielded maximum per cent seed infection.Direct correlation was obtained between seed discoloration and per cent seed infection.The pathogen was found to be present mostly in seed coat and cotyledon and rarely in embryonic axis.The artificial inoculation of 45-day-old plants resulted in maximum disease incidence,resultant seed infection and minimum seed yield /plant and 100 grain weight

The Monoclonal Antibody Cocktail in SARS-CoV 2: A Bonanza for Patients With Chronic Lymphocytic Leukemia?

Monoclonal antibody cocktail is currently one of the most promising approaches being studied in the management of severe acute respiratory syndrome coronavirus 2 (SARS CoV-2). We present a case of an elderly patient with coronavirus disease (COVID-19) and Chronic lymphocytic leukaemia (CLL) who had recurrent episodes of desaturation and admission in intensive care unit (ICU) despite receiving the treatment for moderate to severe COVID-19. After careful selection, weighing the benefits and risks, the patient was started on the combination of the two monoclonal antibodies, casirivimab and imdevimab. The results suggest that this could be a game changer in COVID-19 with a focused approach of management of COVID-19 positive patients especially in the vulnerable population

Evaluation of Hypervelocity Carbon Dioxide Blunt Body Experiments in an Expansion Tube Facility

This work represents efforts to study high-enthalpy carbon dioxide flows in anticipation of the upcoming Mars Science Laboratory (MSL) and future missions. The current study extends the previous presentation of experimental results by the comparison now with axisymmetric simulations incorporating detailed thermochemical modeling. The work is motivated by observed anomalies between experimental and numerical studies in hypervelocity impulse facilities. In this work, experiments are conducted in the Hypervelocity Expansion Tube (HET) which, by virtue of its flow acceleration process, exhibits minimal freestream dissociation in comparison to reflected shock tunnels. This simplifies the comparison with computational result as freestream dissociation and considerable thermochemical excitation can be neglected. Shock shapes of the Laboratory aeroshell and spherical geometries are compared with numerical simulations. In an effort to address surface chemistry issues arising from high-enthalpy carbon dioxide ground-test based experiments, spherical stagnation point and aeroshell heat transfer distributions are also compared with simulation. The shock stand-off distance has been identified in the past as sensitive to the thermochemical state and as such, is used here as an experimental measureable for comparison with CFD and two different theoretical models. For low-density, small-scale experiments it is seen that models based upon assumptions of large binary scaling values are unable to match the experimental and numerical results. Very good agreement between experiment and CFD is seen for all shock shapes and heat transfer distributions fall within the non-catalytic and super-catalytic solutions

Experimental and Numerical Investigation of Hypervelocity Carbon Dioxide Flow over Blunt Bodies

This paper represents ongoing efforts to study high-enthalpy carbon dioxide flows in anticipation of the upcoming Mars Science Laboratory and future missions. The work is motivated by observed anomalies between experimental and numerical studies in hypervelocity impulse facilities. In this study, experiments are conducted in the hypervelocity expansion tube that, by virtue of its flow acceleration process, exhibits minimal freestream dissociation in comparison with reflected shock tunnels, simplifying comparison with simulations. Shock shapes of the laboratory aeroshell at angles of attack of 0, 11, and 16 deg and spherical geometries are in very good agreement with simulations incorporating detailed thermochemical modeling. Laboratory shock shapes at a 0 deg of attack are also in good agreement with data from the LENS X expansion tunnel facility, confirming results are facility-independent for the same type of flow acceleration. The shock standoff distance is sensitive to the thermochemical state and is used as an experimental measurable for comparison with simulations and two different theoretical models. For low-density small-scale experiments, it is seen that models based upon assumptions of large binary scaling values do not match the experimental and numerical results. In an effort to address surface chemistry issues arising in high-enthalpy groundtest experiments, spherical stagnation point and aeroshell heat transfer distributions are also compared with the simulation. Heat transfer distributions over the aeroshell at the three angles of attack are in reasonable agreement with simulations, and the data fall within the noncatalytic and supercatalytic solutions

Statistical theory of timedependent diffusioncontrolled reactions in fluids and solids

The transient effect in a diffusion limited reaction is described by a time-dependent rate coefficient: k(t) = a + b exp(c 2 t)erfc(ct 1/2), where a, b, and c are expressed in terms of the diffusion coefficient (D), the encounter distance (R), and the absolute rate coefficient (k a ); and for ionic reactions, the Onsager length (r e ). Time resolved fluorescence quenching studies on cresyl violet-potassium iodide system in water confirm the validity of the above equation. The values of D and R obtained from the fluorescence quenching studies are in good agreement with the values inferred from other sources, and the value of ka is reasonable

Virus-induced gene silencing database for phenomics and functional genomics in Nicotiana benthamiana

Virus-induced gene silencing (VIGS) is an important forward and reverse genetics method for the study of gene function in many plant species, especially Nicotiana benthamiana. However, despite the widespread use of VIGS, a searchable database compiling the phenotypes observed with this method is lacking. Such a database would allow researchers to know the phenotype associated with the silencing of a large number of individual genes without experimentation. We have developed a VIGS phenomics and functional genomics database (VPGD) that has DNA sequence information derived from over 4,000 N. benthamiana VIGS clones along with the associated silencing phenotype for approximately 1,300 genes. The VPGD has a built-in BLAST search feature that provides silencing phenotype information of specific genes. In addition, a keyword-based search function could be used to find a specific phenotype of interest with the corresponding gene, including its Gene Ontology descriptions. Query gene sequences from other plant species that have not been used for VIGS can also be searched for their homologs and silencing phenotype in N. benthamiana. VPGD is useful for identifying gene function not only in N. benthamiana but also in related Solanaceae plants such as tomato and potato. The database is accessible at http://vigs.noble.org.Noble Research Institute and NSF IOS-102564